As more devices and appliances are designed for ease of use by individuals, speech recognition has become a more common feature. The use of speech recognition allows an individual to communicate with and provide commands to a device with minimal usage of an input controls such as a keypads, buttons, dials, or other controls.
However, vocal patterns for a particular word or phrase may vary widely from one individual to another. In conventional speech recognition, a device generally either is designed to respond to many different vocal patterns, or is trained or programmed to respond properly to the commands of a particular individual. If a device is designed to respond to the speech commands made in many different vocal patterns, it is likely the device will not respond accurately to all commands and may require that commands be repeated multiple times until commands can be understood. The numerous and wide variations that occur in speech patterns may make it very difficult to respond correctly to all commands from all individuals. However, if devices are instead trained to respond to an individual's voice commands, then the individual repeats this training process for each device to be commanded. Further, if multiple users are to command the same device, then each of the users undergoes through the same training process to enable the device to respond to voice commands.
If many types of devices are subject to voice command, in conventional systems each device has its own speech recognition system, comprised of all hardware and software needed for speech recognition. For example, each such device may have a microphone, an analog to digital converter, and a digital signal processor. The addition of these items to each device being commanded can result in a great deal of added expense for the design and manufacture of devices with speech recognition capability.